Department of Neurological Surgery, The University of Washington, Seattle, WA 98195, USA.
J Neural Eng. 2013 Jun;10(3):036021. doi: 10.1088/1741-2560/10/3/036021. Epub 2013 May 13.
Recently, electrocorticography-based brain-computer interfaces have been successfully used to translate cortical activity into control signals for external devices. However, the utility of such devices would be greatly enhanced by somatosensory feedback. Direct stimulation of somatosensory cortex evokes sensory perceptions, and is thus a promising option for closing the loop. Before this can be implemented in humans it is necessary to evaluate how changes in stimulus parameters are perceived and the extent to which they can be discriminated.
Electrical stimulation was delivered to the somatosensory cortex of human subjects implanted with electrocorticography grids. Subjects were asked to discriminate between stimuli of different frequency and amplitude as well as to report the qualitative sensations elicited by the stimulation.
In this study we show that in humans implanted with electrocorticography grids, variations in the amplitude or frequency of cortical electrical stimulation produce graded variations in percepts. Subjects were able to reliably distinguish between different stimuli.
These results indicate that direct cortical stimulation is a feasible option for sensory feedback with brain-computer interface devices.
最近，基于脑电的脑机接口已成功地将皮质活动转化为外部设备的控制信号。然而，如果能提供躯体感觉反馈，此类设备的实用性将会大大增强。直接刺激躯体感觉皮层会引起感觉知觉，因此这是一种很有前途的闭环方法。在将其应用于人类之前，有必要评估刺激参数的变化如何被感知，以及它们在多大程度上可以被区分。
向接受过脑电皮层电极植入的人类受试者的躯体感觉皮层施加电刺激。要求受试者对不同频率和幅度的刺激进行区分，并报告刺激引起的定性感觉。
在这项研究中，我们表明在接受脑电皮层电极植入的人类中，皮质电刺激的幅度或频率的变化会产生感知的分级变化。受试者能够可靠地区分不同的刺激。
这些结果表明，直接皮层刺激是脑机接口设备感觉反馈的一种可行选择。
